<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>15-断点的演示</title>
</head>
<body>
  <script>
    let num = 10
    num = num + 1
    console.log(num);
  </script>
</body>
</html>